Small or declining populations are vulnerable to inbreeding and random loss of genetic variation through genetic drift. In changing environmental conditions, it is important to determine the level of genetic diversity and the factors influencing the maintenance of genetic diversity for conservation management. An important factor that affects the amount of genetic diversity in a population is the effective population size (Ne), which is greatly influenced by the mating system of a species. In a polyandrous mating system, females mate with several males, which may result in multiple paternity of clutches. In such a mating system, Ne is increased, and as a result less genetic variation may be lost compared to monogamous mating system. Hence, it is important to have a complete knowledge of the mating system of the endangered Malaysian green and hawksbill turtles because it is relevant to conservation plans aimed at preventing the extinction of these species.

The main objectives of this study were: (i) a first genetic test of mating behaviour in hawksbill turtles; (ii) to determine the level of multiple paternity within broods in two Malaysian populations of green turtle from Sabah Turtle Islands Park (STIP, Sulu Sea) and Terengganu (South China Sea); (iii) to determine if the same male(s) sired successive clutches of individual females over repeated laying periods, and in the case of multiple paternity within clutches to see whether relative reproductive success of different males varies across successive clutches.

Map of Malaysia showing the location of sampling sites for the paternity study

Withdrawing blood sample from green turtle hatchling

This research was funded by Universiti Malaysia Terengganu, Royal Holloway University of London and the Public Service Department of Malaysia. Special thanks to the Fisheries Department of Malaysia and the Department for the Environment, Food and Rural Affairs, United Kingdom for approving the CITES permit (permit no: MY FSHQ/226/04). Special thanks also goes to Sabah Parks for providing field assistance and logistic at Sabah Turtle Island Parks.